autotools: Fix for autoconf-archive 2019.01.19

The code coverage macros from the archive changed in a backward
incompatible way. This adds a workaround to autodetect either version
and do the right thing.

Tested:
    Against the typical, older autotools and the new autotools
    2019.01.09 in the CI environment.

Change-Id: I765ec46051c2666874dce51675092aa4da989ec5
Signed-off-by: William A. Kennington III <wak@google.com>
diff --git a/.gitignore b/.gitignore
index 5c5f8c1..288aef3 100644
--- a/.gitignore
+++ b/.gitignore
@@ -42,6 +42,7 @@
 *.la
 *.so*
 *.pc
+/aminclude_static.am
 /config.h
 /config.h.in~
 /config.log